To retrieve e-mail from mailboxes and create tasks from them, you need to set up mailbox checking on your desired schedule.

Using CRON on a UNIX/Linux/Mac OS X server you can set up a CRON job to load the check_mailboxes.php page every 15 minutes to retrieve e-mails and create tasks from them. On windows, I know you can schedule a task to do the same thing - someone tell me how and I'll add it here.

The your-password below is the 'Password for CRON Jobs' in your Server Settings.

Here is the syntax for 2 ways to retrieve messages every 15 minutes using CRON.